Transmission warning - Should I brace myself?

[galois]

Hi

Just took out our e39 today. Unfortunately the transmission warning light stayed on rather than blinking out like normal. Reading up when we got home (and some guessing) it seems to be one of:

Cold transmission oil just taking a lot longer to warm up and we didn't leave it long enough;
Alternator/battery on the blink - could be, it has been taking just a little bit longer for the glow plugs to work and to turn over.
Transmission dead and we are on the hook for thousands

So much for old BMW diesel's being bombproof. We have already done the turbo this year! A lot of me is thinking we should just jack it in and get something new, and under warranty and swallow the massive depreciation!

Any thoughts on what it is likely to be? Or on whether I should sell the Westfield to cover the bill

[PhillipM]

At least you get a warming light, mine just exploded.
I'll have to buy a BMW!

[Parrot of Doom]

If the transmission still shifted normally I can't imagine that its much to worry about.

[agentsmith]

is the light on still? I had this once on mine caused by the battery charge level being too low. If it's on still, suggest you track down a transmission expert.

[agentsmith]

ps. if you are in hants or berks. try these guys: http://www.3dtransmissions.co.uk/

[galois]

The shifting wasn't abnormal. That said we only got ~2 miles total. Will be straight to the local BMW dealer tomorrow morning (~7 miles) for diagnostics. Can you tell we are both very worried and not really sure what we can/can't do without making it worse?

A new battery/alternator seems like it might be at the cheaper end of the spectrum!

[galois]

Quick update:

Just taken the car out for a test run this afternoon and the light stayed off the whole time. Suggests either an electrical gremlin or something thrown up by the transmission oil not having warmed up properly. All gears were changing normally.

Thanks for your help and for recommending a local specialist (in case this resurfaces)

[Chris944_S2]

When my alternator went earlier this year it threw up a transmission error message.
I'd have the alternator checked first. Also if your batery is old its worth replacing anyway, specially now that its gone cold.

[Parrot of Doom]

galois said:

Quick update:

Just taken the car out for a test run this afternoon and the light stayed off the whole time. Suggests either an electrical gremlin or something thrown up by the transmission oil not having warmed up properly. All gears were changing normally.

Thanks for your help and for recommending a local specialist (in case this resurfaces)

When was the ATF last changed? It should be every 50-80,000 miles or so, along with the filter and any gaskets. Its an easy job on most cars, and well worth doing.

It might also be the case that some of your car's electronics are slightly damp.